Colorectal Cancers: Colon (Thick Intentisinal) and Rectal Cancer

Nearly one million people around the world are diagnosed with colon (colon) and rectal cancer, also known as colorectal cancers. Colorectal cancers are among the top five most common cancers in our country according to the data of the Ministry of Health. Early diagnosis and treatment are of vital importance in colorectal cancer, which is one of the more common types of cancer in men and causes the most loss of life.

• What are colorectal cancers?
• Cancer that occurs in the lining of the large intestine, which is about 1.5 meters long, is called colon cancer. This type of cancer is caused by the uncontrolled growth of cells and cell clusters in the lining of the large intestine. The last 15-20 cm of the large intestine network is called the rectum, and the cancer that develops here is called rectum cancer. The term colorectal cancers are used to describe two types of cancers.
• Colorectal cancers can be seen at any age. The average age of occurrence is 63 years. However, according to research, one-third of patients diagnosed with colorectal cancer are under 55 years old. It is noteworthy that the incidence has increased in young people especially in recent years.

• What are the risk factors?
• Although the exact cause is not known, factors that increase the risk of colorectal cancer can be listed as follows:
• + Advanced age
• + Presence of polyps in the intestine (especially those with adenomatous pathology)
• + Family history on colorectal cancer.
• + Some genetic disorders that cause significant changes in genes
• + Having an inflammatory bowel disease such as colitis or Crohn's disease, which may cause cancer by disrupting the intestinal cell type within a certain period of time.
• + History of ovarian, breast and uterine cancer in women
• + Excessive consumption of processed and animal foods and less fruit and vegetables
• + Smoking
• Especially people with these risk factors should have screening tests regularly to prevent colorectal cancer.

• What are the prevention methods for colorectal cancer?
• In addition to regular examinations, avoiding smoking and alcohol, adopting a lively lifestyle, not overdoing fat and red meat consumption, eating rich in cereal and fiber foods are protective against colorectal cancers. 

• What are the symptoms of colorectal cancer?
• The onset of colorectal cancers is cell growths in the intestine which is polyps. Polyps usually cause no complaints at first. However, as they get older and their numbers increase, they cause changes in the defecation habits of the person.
• + Prolonged constipation or diarrhea, change in the smell and consistency of stools,
• + Anemia caused by iron deficiency,
• + Thin stools
• + Having blood mixed with stool or rectal bleeding after using the toilet
• + Abdominal pain, loss of appetite and involuntary weight loss may be signs of colorectal cancer.
• These findings alone do not indicate colorectal cancers. However, a person who has these complaints and whose family has bowel, breast, ovarian or cervical cancer should definitely consult a physician.

• How is colorectal cancer diagnosed?
• + Diagnosis of colorectal cancers:
• + Colonoscopy,
• + Hidden blood in stool,
• + Computed tomography (CT) colonography,
• + Flexible sigmoidoscope,
• + It is placed in stool by DNA tests.

• How are colorectal cancers treated?
• The main treatment of colon and rectum cancer at all stages is surgery. Chemotherapy (drug therapy) and radiotherapy (radiation therapy) are the most frequently used methods. It is very important to obtain accurate information about the general condition of the patient and the extent of the disease before planning any treatment.
• Mode of surgical treatment; the mode of treatment for colorectal cancers may vary according to the complications developed such as the colon and rectum, size and stage of congestion occurred, perforation, bleeding complications. Nowadays laparoscopy applications have become increasingly common in the surgical treatment of colon and rectal cancer. The main techniques applied are:
• Local excision: It is the excision of the tumor part through the anus in some small rectal tumors.
• Resection: It is the partial or complete removal of the large intestine, or the rectum, depending on the location of the tumor. In this surgical technique, lymph nodes are removed together with the intestine. If the tumor has spread to neighboring organs, these organs may also need to be removed during radical surgery. The remaining healthy gut ends from the removed intestine are bound.
• After colon or rectum resections, an artificial anus can be created by suturing the small intestine or colon to the abdominal wall when necessary. The contents of the intestine drain from this artificial anus into the plastic bag attached to the abdominal wall. While this situation may be permanent in some patients, it is applied temporarily in some patients. 
• In advanced stage colon and rectum cancers that cannot benefit from radical surgical treatment, palliative surgical procedures such as colostomy can be applied to increase the comfort of the patient's life. III. and IV. Chemotherapy and / or radiotherapy can be added to the treatment before and / or after the operations of the patients at the stage of surgery.

• What are the stages of colon and rectum cancer?
• Stage I: It is the earliest stage. Cancer cells hold the inner and middle layers of the intestine. There is no involvement in lymph nodes and distant organs.
• Stage II: Cancer cells hold all layers of the intestine, reach the outermost layer, and can spread to neighboring organs. There is no involvement in lymph nodes and distant organs.
• Stage III: Regardless of the level of involvement in the intestinal wall, there is tumor spread in the lymph nodes adjacent to the intestine.
• Stage IV: It is the most advanced stage of the disease. Regardless of the tumor spread in the intestinal wall or lymph nodes, there is metastasis in organs such as liver, lung, peritoneum (peritoneum), bone, brain.

• What is the relationship between ulcerative colitis and Crohn's disease and colorectal cancer?
• Ulcerative colitis or Crohn's disease is chronic inflammation of the tissues lining the large intestine. Both are risk factors for the development of colorectal cancer. Especially in people with ulcerative colitis for more than 10 years, colorectal cancer is likely to develop even if there is a response to treatment. For that, even though there is no active complaints developed, but the patients with such kinds of diseases should continuously undergo regular colonoscopy examinations.
• Colorectal cancer is likely to develop from Crohn's disease patients, in areas with intestinal strictures increased by this disease. In case of the presence of such diseases along with smoking habits, the risk of colorectal cancer will be increased again.

Assoc. Prof. Dr. İsmail SERT

General Surgery